Airplane mail pickup



Sept. 17, 1935. I 1 CLAMP|TT 7 2,014,557

AIRPLANE MAIL PI CKUP Filed July 1, 1955 2 Sheets-Sheet 1 IIIIIIIIIH g.4 ACZo/wegs.

Sept. 17, 1935. E. CLAMPITT Q 2,014,557

AIRPLANE MAIL PICKUP Filed July 1, 1955' 2 Sheets-Sheet 2 v Inventor,[/me/ C/am, 9/511 Attorneys.

Patented Sept. 17, 1935 UNITED STATES- AIRPLANE MAIL PICKUP ElmerClampitt, Indianapolis, Ind., assignor of one-third to Harry R. Champ,Indianapolis,

Ind.

Application July 1, 1935, Serial No. 29,202

10 Claims.

This invention relates to means for picking up articles from the groundby flying airplanes. One particular use of the invention is that inpicking up sacks of mail at various stations or airports withoutrequiring the airplane to land and take off so that considerable timemay be saved in the schedule of the mail carrying plane betweenterminals.

An important object of my invention is to provide an apparatus to becarried by the plane which willv permit the picking up of the stationaryarticle'by the plane without imparting a severe shock thereto. A furtherimportant object is to provide a device which will permit engagementwith the article to be picked up without immediately starting thatarticle into motion corresponding to that of the plane but willautomatically compensate for the inertia of the article and then pullthe article in toward the plane as the plane accomplishing the aboveindicated objects, in

cluding a mast for carrying the article to be picked up having certainadvantages, namely that of permitting easy and quick mounting of thearticle thereon and for cooperating with the plane mechanism so as toinsure pick up of the 7, article.

Reference is made to the accompanying drawings wherein one particularform of my invention is illustrated, Fig. 1 being a side elevation ofthe structure embodying my invention;

Fig. 2, a side elevation of a plane carrying my invention;

Fig. 3, a top plane view of the ground tower;

Fig. 4, a front elevation of the tower;

Fig. 5, a detail on an enlarged scale in left hand side elevation of theplane carried mechanism;

Fig. 6, a top plan view of the plane carried mechanism; g

Fig. 7, a vertical longitudinal section on the line in Fig. 6;

Fig. 8, a detail on'a stillfurther enlarged scale in right handelevation of the plane carried mechanism, and

Fig. 9, a rear. elevation thereof.

Like character of reference indicate like parts throughout the severalviews in the drawings.

Referring first to Figs. 3 and 4 illustrating the ground tower, Iprovide a base In centrally of which is carried a post II to extendvertically 5 therefrom for a considerable distance. The post H isrevolubly carried within a standard l2 and a lever I3 is fixed to thepost I I to have a downturned leg M, Fig. 1, which may drop into any oneof a plurality of holes I5 placed about the base l0. By liftingthe.lever l3, the leg II is withdrawn from the hole l5 and by pullingthe lever 03 around, the post ll may be correspondingly revolved andsecured in any desired position by dropping the lever l3 to carry theleg I4 into the selected hole l5. t

On the top end of the post H is carried a bow l8, here shown as beingsubstantially circular with the upper portion cut away. The bow iscentrally carried to extend above the top end of the post II and has ashield l'l secured across its lower portion to cover over from one sidethe lower portion of the bow and the upper end of the post II. Theshield i1 is preferably curved around at its lower end, Fig. 1, toprovide a smooth roundan extended axis of the post II as indicated inFig. 4 so that the center of the bow l6 may be indicated by theintersection of the light beams to guide the aviator at night.

From the upper ends of the bow I6, I turn rearwardly and outwardly ineach case a wing or guard l9 to have the wings diverging one from theother and be inclined downwardlysomewhat from the horizontal. Thesewings or guards l8 are preferably elastic in nature to some extent or atleast will spring some at their junctions with the 40 upper ends of thebow IS...

The article to be picked up, here indicated as a mail bag 20, isprovided with a looped carrier 2| in the nature of a cord or cable. I Ateach upper end of the how "i is a forwardly directed pin 22 over whichpin the cord 2| is'hung. Each side of the looped cord 2| is spread topass around forwardly turned arms 23, one on each side extending fromthe bow IS. The bag 20 is thus supported merely by its downward pull onthese pins. The sack 20 is carried up and placed in the hanging positionby an operator who climbs the ladder 24 carried by the post I I, theupper end of the ladder having an extension 25 which maybe pushedupwardly to permit engagement with the cord 2| on the upper pins 22 andside pins 23 and then be pulled down out of the way.

The cooperating mechanism carried by the plane 23 is mounted preferablyon the floor 21 of the plane. A drum-23, Fig. '7, having side plates 23and 33 is revolubly mounted on an axle 3| between supporting plates 32and 33. A spring 34 is secured by one end to the axle 3| and by the.other end to the drum 28, the spring 34 being confined entirely withinthe drum. A cable 35 is wound around the drum on its outer side. Bymeans of a crank 33 secured to an outer projecting end of the axle 3|,the spring 34 may be wound up to give the desired pull on the drum 23.The cable 35 is so wound around the drum 23 as to pull off rearwardlyfrom the under side of the drum and pass over a roller or bar 31 mountedbetween the plates 32 and 33.

From the rear end of the plates 32 and 33 is suspended a lever system tohang from the under side of the floor 21 in a rockable manner. An arm 33is fixed to a bar 33 to have a leg 43 hinged thereto by one end. The arm38 is preferably provided with a flexible portion 4| in the nature of afiat steel spring so as to permit a yielding motion of the arm 33laterally of the plane. The bar 33 is revolubly carried betweenprojecting brackets extending from the plates 32 and 33 and a lever 42is fixed by one end to the bar 33 as a means of rocking the bar. Theother end of the lever 42 is interconnected with an operating lever 43by means of a link 44 so that by swinging the lever 43, the arm 33 maybe swung correspondingly.

RockabLv mounted on the bar 33 is a lever 45 from the outer end of whichpivotally hangs a link 43 to have its lower end pivotally engaging withthe leg or foot 43 at a distance removed from the hinged connection ofthe leg 43 with the arm 33. From the hub of the lever 45 on the bar 33,extends another lever 41 angularly therefrom in the nature of a bellcrank. From the outer end of this lever 41 extends a link 43 forwardlyto the lower end of a control lever.

43, both levers 43 and 33 herein shown as being mounted on the same axle33.

Normally the arm 33, link 43 and leg 43 are carried in the position asindicated by the dash lines in Figs. 1 and 8 wherein those members arebrought around up against the under side of the fioor 21 to extendrearwardly thereunder.

A trap door 3| is provided in the floor 21 and bysuitable manipulationof the levers 43 and 43, the outer end of the leg 43 is presentedthrough the opening normally closed by the door 3| as indicated by thedot-dash lines in Fig. 8. When the outer end of the leg 43 is thuspresented, a hook 32 on the end of the cable 35 is attached to this endof the leg by means of a conical plug 33, preferably made of rubber togive an elastic grip, and is pressed into the endof the leg. The leg 43is preferably made to have a U-section, Fig. 5, and the plug 53 ispressed between the side members of the leg 43 at its outer end asindicated in Fig. 5. The levers 43 and 43 are then suitably manipulatedso as to first allow the leg 43 to swing around downwardly with itsattached hook 52 and then have the arms 33 and 45 swing slightlyrearwardly, all to the solid line positions as indicated in Fig. 8,wherein a length of the cable 33 rests within the leg 43 extendingupwardly from the plug 53. Preferably, although not necessarily so, thecable 35 passes between fingers 54 and 55 carried on the rear side ofthe link 43 near its hinged connection with the lever 45, the cablebeing free to be carried rearwardly from between the fingers. The link43 is preferably provided with a fiexible link 53 corresponding to thelink 4| of the arm 33 so that both the link and the arm may yieldslightly laterally of the plane.

The cable 35 is provided with a knot 51 as a means of preventing thespring 34 from pulling on the cable 35 tending to pull-it back aroundthe drum 23, the knot '51 being caught on the rear side of a bar 53 bylifting the cable 35 upwardly thereunder and into a V-notch 53, Fig.

9. Thus the spring 34 may have an initial tension on the cable 35 fromthe bar 53 but the outer end beyond the notch 51 hangs freely downwardlyand behind the members above indicated to have the hook 52 supported bythe outer end of the leg 43. It is to be observed that the open end ofthe hook 52 is turned in the forward direction of the plane.

Now with the book 52 presented by the leg 43 in the extended positionunder the floor 21, the plane 23 is brought over the bow l3 to have thehook 52 brought up on as near a center line between the guards l3 as ispossible and at an elevation which will cause the hook 52 to engage theupper horizontally disposed length of the cord 2|, the hook 52 beingpermissibly allowed to come below that line since the rear 111-clination of the leg 43 will cause the cord 2| to relatively slide downinto engagement with the hook 52 as the plane proceeds forwardlythereover. Any forward pull on the cord 2| will, of course, cause it tobecome disengaged from the pins 22 and 23 without any substantialresistance.

Immediately the hook 52 engages the cord 2| and thereby dislodges itfrom its support by the bow IS, the weight of the bag 23 is then carriedby the hook and in turn by the cable 35. This applied weight will causethe cable 35 to be pulled downwardly to slide the knot 51 down fromengagement against the rear side of the bar 53 and thus permit thespring 34 to exert its pull on the cable 35. Since there is an evidentamount of inertia in the bag. 23, the first result is that the cable 35is actually pulled rearwardly to unwind from the drum 23 as the planeproceeds forwardly, thereby winding up the spring 34 and graduallydecelerating the relative rear travel of the sack 23 until such abalance is reached that the bag 23 and the plane 23 move forwardly atthe same speeds. When this balance is reached, the spring 34 is of thatstrength that 55 it willthen begin gradually to revolve the drum 28 inthe opposite direction to wind the cable 35 therearound until the bag 23is presented at the opening covered ordinarily by the door 5|.

If the tension of the spring is not sufiicient to so accomplish thisresult, the axle 3| may be revolved by means of the crank 33 to applyadditional tension to the spring and thereby complete the operation ofbringing the mail bag up within the plane. The length of thecable 35 mayrange over a considerable length such as from 100 to 300 feet, dependingupon several factors, such as the speed of the plane, height of the postII, and the usual weight of the sack The mail sack will not come backagainst the plane with increasing velocity but rather the speed of thereturning sack will be somewhat slowed down by reason of the outerportion of vthe spring 34 coming into contact with the in- This mayfurther be regulated by means of the lever 36 being set such that thespring 34 will be sufiiciently'unwound by the time the sack comes withina few feet of the plane as to just balance the weight of the sack andthen further return is accomplished by returning -the crank 36 as aboveindicated.

When the sack reaches that position, it may be grasped by the operatorand the cable disengaged whereupon the levers 43 and 49 may then bemanipulated from 'within the plane to carry the leg on around and upagainst the floor 21 to its normal inoperative-position. Of course anylateral deviation from the desired course of the plane 26 in approachingthe bow l6, may be compensated to some extent by'the leg 40 striking oneor the other of the guards l9 so as to guide the hook 52'on up to theupper side of the cord 2l carried therebetween at their forward ends,the leg 40 being permitted tobe carried laterally somewhat by the guardI9 asthe case may be through the flexible portions H and 56 in the arm38 and the link 46.

While I have herein shown and described my invention in the form as nowbest known to me, it is obvious that structural changes may be madewithout departing froifilahe spirit of the invention and I, therefore,do not desire to be limited to that precise form beyond the limitationsas'may be imposed by the following claims.

I claim: 1.' In an airplane article pickup system, a drum carried by theplane, spring means resisting unwinding of the drum, a cable wound aboutthe drum, a foot carried by the airplane to swing downwardly therefrom,a hook on the cable adapted to be carried by the foot at its lower end,and a ground member having an opening across its upper end, an articlecarrying cord releasably extended across .the opening, said hook beinghooked under said cord upon flight of the airplane, the inertia of saidarticle initially causing said cable to unwind from said drum and windsaid spring, said spring overcoming said inertia pull and then unwindingto wind up the cable and draw the article against wind resistance to theairplane.

2. In an airplane article pickup system, a drum carried by the plane,spring means resisting unwinding of the drum, a cable wound about thedrum, a foot carried by the airplane .to swing downwardly therefrom,- ahook on the cable adapted to be carried by the foot at its lower end,and a ground member having an opening across its upper end, an articlecarrying cord releasably extended across the opening, said hook beinghooked under said cord upon flight of the airplane, the inertia of saidarticle initially causing said cable to unwind from said drum and windsaid spring, said spring overcoming said inertia pull and then unwindingto wind up the cable and draw the article against wind resistance to.

the airplane, said cable being initially carried to have a substantialpart thereof wound on said drum, with the spring substantially unwound.

3., In an airplane article pickup system, a drum carried by the plane,spring means resisting unwinding of the drum, a cable woundabout thedrum, a leg carried by the airplane to swing downwardly therefrom, ahook on the cable adapted to be carried by the leg at its lower end, anda ground member having an opening across its upper end, an articlecarrying cord releasably extended across the opening, said hook beinghooked under said cord upon flight of the airplane, the

inertia of said article initially causing said cable to unwind from saiddrum and wind said spring, said spring overcoming said inertia pull andthen unwinding to wind up the cable and draw the article against windresistance to the airplane, 3 5

said cable being initially carried to have a substantial part thereofwound on said drum, with the spring substantially unwound, and meansreleasably holding the outer end of the cable extending to said leg endto be without initial pull 10 from said spring, said means beingrendered inoperative upon pull on said hook.

4. In an airplane article pickup system, a drum carried by the plane,spring means resisting unwinding of the drum, a cable wound about the 15drum, a foot carried by the airplane to swing downwardly therefrom, ahook on the cable adapted to be carried by the foot at its lower end,and a ground member having an opening across its upper end, an articlecarrying cord releasably 20 extended across the opening, said hook beinghooked under said cord upon flight of the airplane,

. the inertia of said article initially causing said cable to unwindfrom said drum and wind said spring, said spring overcoming said inertiapull 25 and then unwinding to wind up the cable and draw the articleagainst wind resistance to the airplane, and means for varying thedegree of rewinding of the cable.

5. In an airplane article pickup mechanism, a 30 revoluble drum carriedby the airplane, a cable wound about the drum, a spring normally tendingto turn the drum to wind up said cable, a leg swingably carried by theairplane, a hookon said cable and means releasably attaching the hook 35to said leg, said cable initially being substantially entirely wound onthe drum with the spring substantially unwound.

6. In an airplane article pickup mechanism, a

wound about the drum, a spring normally tending to turn the drum to windup said cable, a leg swingably carried by the airplane, a hook on saidcable and means releasably attaching the hook to said leg, said cableinitially being substantially ,5 entirely wound on the drum with thespring substantially unwound, a knot on the cable determining its woundposition, and a notched mem-" ber' above the pathof the unwinding cablewhereby said cable may be lifted into the notch of the 5 member to havesaid knot strike thereagainst and limit winding of the cable, said cablebeing pulled from said notch by pull of an article engaged by said hook.

'7, In an airplane article pickup mechanism, a 55 cable carried by theairplane, an article engaging member flxed to the cable, an arm rockablycarried to swing downwardly from the airplane, a foot hinged to the armtmhang therefrom, a link hinged to the foot at a distance from its hingeo connection with said arm, a lever engaging the upperend of said link,and an operating lever interconnected with the upper end of said am,said link engaging lever serving toswing said .foot on said arm and saidoperating lever serv- 5 ried to swing downwardly from the airplane, afoot hinged to the arm to hang therefrom, a link hinged to the foot at adistance from its hinge connection with said arm, a lever engaging theupper end of said link, and an operating lever interconnected with theupper end of said arm, said link engaging lever serving to swing saidfoot on said arm andsaid operating lever serving to swing both the armand foot in unison whereby the arm and foot may be swung in extendedrelation back under the airplane, or the foot folded up to have itslower end presented adjacent the upper end of the arm, and meansreleasably interconnecting said article engaging member with said footlower end, said arm and said link having portions thereof flexiblelaterally of the airplane.

9. In an airplane article pickup system, means carried by the airplaneto engage an article, and ground means for presenting the articlecomprising a post, an upturned bow on the upper ends of the post, alooped cord for carrying an article,

and a pin at each upturned end of said bow across which pins said loop.is hung to depend therefrom, and a guide arm extending rearwardly fromeach of said bow ends and diverging one from the other, and a transverseshield across the lower portion ofsaid bow in front of which saidarticle may hang from said cord.

10. In an airplane article pickup system, means carried by the airplaneto engage an article, and ground means for presenting the articlecomprising a post, an upturned bow on the upper end of the post, alooped cord for carrying an article, and a pin at each upturned end ofsaid how across which pins said loop is hung to depend therefrom,

and a guide arm extending rearwardly from each 15

